On my previous blog posting, I discussed about finding best and efficient method of washing dirty clothes. To capture the big picture I already used mind map. Now to find the best solution, I will use life cycle calculation.

Step 2 – “FEASIBLE alternatives”

From my previous blog, here is my mind mapping:

Step 3- Develop the outcomes for each alternative (minimum 2)

My wife and I simplify the choices to:

Laundry per kg,

Single tub Top Load Washing Machine and

Front Load Washing Machine

as they are less time consuming and affordable for a long term. For the top load machine I will use data of Electrolux EWT – 7045 and for the front load, Samsung WM WF – 8650 NHw. I saw them in Lottemart display and they have the same washing capacity 7 kg.

Step 4- Selection of the acceptable criteria

Data below shown specification and also operational cost per month of washing machine:

Assumption, washing done once every 2 days (15 x per month).

And table below show cost I will pay per month if I choose laundry per kg service.

Step 5- Analysis/ Comparison of the Alternatives against the Criteria

Cumulative cost I will pay for each alternative are summarized in table below:

Laundry per kg is cheap for a short period of time. But for long term, buying a washing machine is a good investment.

Step 6- Selection of the Best/ Preferred Alternative Compared against the Criteria

For three years comparison, the most economical choice is to buy Electrolux Top Load for my washing needs. The front load machine has lower wattage consumption but it’s not significantly affect the total cost involved.

After buying the top load machine, I have to take care of the machine as instructed on the guide, so that my machine will be everlasting. That way, I can avoid another cost like repairing cost / the need to buy a new machine.

You also would be wise to do some research on SIMPSONS PARADOX or SIMPSONS RULE.

In your case, you are making a decision based ONLY on two models and there is a big danger in that…… Because your sample size is so small, (your alternatives) you may very well have created a distorted or BIAS…..)

I will accept this but what I would suggest you do is to use this same case study for another blog, but FIRST apply some form of multi-attrbute decision making on top loading vs front loading machines. And THEN, once you have determined which of those is “better” for your purpose, you should pick at least 5-7 models to do your cost analysis on. BTW, you would also be wise to check on the average LIFE of the two types of machines. I think you will find that the Front Loading machines have a considerably longer life expectancy, which will greatly impact your cost analysis. (See Chapter 6 in your Engineering Economy for more about useful lives)